The present invention relates to flexible laminates, and more particularly, to flexible laminates of metal adhered to fabrics.
High strength flexible fabrics are well-known in the art and include fabrics made of, for example, aromatic polyamide fibers and the like. The aromatic polyamide fibers have been made into various forms including fiber bundles, fiber mats and woven and non-woven fabric or cloth. One well-known commercially available woven polyamide aramid fiber is KEVLAR.RTM.. Thermoplastic copolyetherester elastomers are also well-known in the art and have been used as molding compounds. Several commercially-available copolyetheresters are available, e.g., certain HYTREL.RTM. resins and certain LOMOD.RTM. resins.
In U.S. patent application Ser. No. 459,908 filed Jan. 2, 1990 now abandoned, and assigned to the instant assignee, compositions are described which contain polyetherester resin reinforced with aromatic polyamide fibers. In U.S. patent application Ser. No. 459,908, which is incorporated herein by reference in its entirety, good adhesion is exhibited between the polyetherester resin and the aromatic polyamide fibers. In certain embodiments therein, composite structures having layers of plain weave KEVLAR.RTM. fabric of aromatic polyamide fibers and layers of polyetherester film are described.
Metal foils, including, for example foils of copper, aluminum, stainless steel and the like are also well-known in the art and are commercially available. Such metal foils have been used as substrates for making sanding belts, sanding discs, electronic components and the like.
Prior art laminates are described in U.S. Pat. Nos. 4,868,033 and 4,883,708, both of which are incorporated by reference herein in their entirety. Abrasive belts and discs having polyurethane binders and woven backings are described in U.S. Pat. No. 4,331,453, which is incorporated by reference herein in its entirety.
Prior art laminates have also been made by using thermoset resins, such as epoxy resins, to impregnate a woven cloth made from glass or organic polymer fiber rovings, such as polyaramid, to bond metals, such as copper, to cloth made from glass or organic polymer fiber. However, such laminates generally have poor adhesive integrity and either fail to adhere to the cloth or the metal or both when used as substrate for abrasive elements, for example sanding belts, discs and the like, or semiconductor substrates. Thus, it is desirable to improve the integrity of the adhesives used for bonding or adhering metal foils to cloth or fabric substrates, especially when laminates made therefrom are subjected to conditions requiring repeated flexing.